Centralizer



April 23, 1968 Filed March 2l. 1966 C. W. TURBYFILL CENTRALIZER 2 Sheets-Sheet l Il Il Il ll ,Il

INVENTOR.

/I TTORNE YS April 23, 1968 -c. W. TURBYFILL CENTRALIZER 2 Sheets-Shee led March 2l, 1966 INVENTOR.

United States Patent O 3,379,258 CENTRALIZER Charles W. Turbytill, R0. Box 490, Marshall, Tex. 75670 Filed Mar. 21, 1966, Ser. No. 535,921 8 Claims. (Cl. 166-241) This invention relates to a centralizer and more particularly to a centralizer having adjustable hinged collars.

As is well known in the art, centralizers are used in a well bore or bore hole for spacing and positioning tubular members and the like centrally relative to the bore hole.

It is desirable to maintain the centralizer at a predetermined location on the well pipe. Many centralizers presently in use attempt to prevent moving or slippage of the centralizer by inserting wedge members or slips in the space between the tubular member and centralizer collars, or by welding the centralizer collars on the tubular member.

However, it is desirable that the collars on the centralizer t closely adjacent the tubular member to provide a minimum restriction of the well bore annulus. Also, it is desirable to retain the centralizer at a fixed location on the tubular member while at the same time permitting a part of the centralizer to flex, slide or move relative to the pipe if the centralizer bows become compressed by engagement with the well bore walls.

At the present time, many centralizers are held in position by wedge members or slips, which tend to expand the centralizer collars and thereby move them away from the well pipe so as to reduce or restrict the well bore annulus and therefore, flow is restricted in the well bore. Also, the slips or wedge members inserted between each centralizer collar and tubular member prevent the centralizer from moving up or down the tubular member. Thus, sliding, flexing or moving longitudinally of the centralizer relative to the tubular member is prevented if the centralizer bows become compressed for any reason, including engagement with the well bore wall.

At the present time it is also desirable to have a centralizer that does not have to be cut with a cutting torch or the like to remove it from the tubular member.

It is therefore an object of the present invention to provide a new and improved centralizer including spaced hinged collars that are adapted to be positioned around and easily removed from a tubular member.

Yet another object of the present invention is to provide a centralizer including centralizer bows and a pair of spaced hinged collars for positioning around a tubular member wherein the upper collar is adapted to slide longitudinally relative to the tubular member if the centralizer bows become compressed.

Still another object of the present invention is to provide a centralizer for positioning around a tubular member in a well bore wherein the centralizer includes a pair of spaced hinged collars and centralizer bows mounted therebetween and wherein the collars snugly fit adjacent the tubular member around the outer surface thereof which thereby prevents slack or openings betweeny the tubular member and collars to provide a minimum clearance therebetween.

Yet another object of the present invention is to provide a centralizer for positioning around a tubular member in a well bore wherein the centralizer includes a pair of spaced, hinged collars and wherein the lower collar has a pair of slip or wedge member pockets each of which are adapted to receive a slip or wedge member which is used for positioning the centralizer in the well bore by gripping and engaging the tubular member and which does not substantially reduce the clearance between the lower collar and the tubular member.

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Still another object of the present invention is to provide a centralizer including a pair of spaced hinged collars for positioning around a tubular member wherein each of the hinged collars include intermeshed tabs having openings therein for receiving a resilient pin or spring pin which securely positions each of the collars about the tubular member.

The preferred embodiment of this invention will be described hereinafter, together with other features thereof, and additional objects will become evident from such description.

The invention will be more readily understood from a reading of the following specifications and by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown, and wherein:

FIG. 1 is a partial sectional view representing a well bore showing a tubular member therein and a plurality of centralizers of the present invention in elevation thereon;

FIG. 2 is an enlarged cross-sectional View of a well bore showing in greater detail the tubular member and centralizer positioned thereon;

FIG. 3 is a sectional view, partly in elevation, taken along line 3--3 of FIG. 2, illustrating the relationship of the intermeshed tabs of the collars and the resilient pin extending therethrough to retain the tabs in intermeshed relationship;

FIG. 3A is a view similar to FIG. 3 illustrating the relationship of the tabs when forces compress the resilient pm;

FIG. 4 is an elevation of the preferred form of resilient pin used with the centralizer of the present invention;

FIG. 5 is a cross-sectional View of the centralizer positioned around a tubular member and showing in greater detail the wedge members in one of the collars;

FIG. 6 is a cross-sectional view of the present invention positioned around a tubular member taken along the line 6-6 of FIG. 5, and illustrating further details of the wedge member;

FIG. 7 is an enlarged perspective View of one of the slips or wedge members used with the centralizer of the present invention;

FIG. 8 is a partial elevation illustrating the locking Ameans mounted with the intermeshed tabs of the lower collar of the centralizer of the present invention.

Attention is directed to FIG. 1 wherein a plurality of the centralizers of the present invention are generally designated at 10, and are illustrated as being positioned around a tubular member 11 in a well bore 12 having a Well bore wall 12a.

As illustrated in FIGS. 1, 2, and 5, a pair of spaced collars 15 and 16 are adapted to be positioned around the tubular member 11 and mounted therebetween are a plurality of spaced arcuate bows 17. The bows 17 are y secured at each end 17a and 17b to the spaced collars 15 and 16, respectively, by any suitable means such as welding and extend longitudinally relative to the tubular member 11. The bowfs 17 are outwardly, arcuately curved and are adapted to engage and contact the well bore wall 12a to center the tubular member 11 in the well bore 12 so that drilling muds, iluids and the like may flow in the well bore 12 with a minimum restriction from the tubular member 11 and the centralizer 10. Also in cementing operations, it is desirable to provide as near uniform sheath of cement in the annulus as possible to avoid thin cement layers between the tubular members and bore wall 12a. It should be understood that the spaced collars 15 and 16 and bows 17 are preferably formed, constructed or cast from hardened steel and the like, but may be constructed from any other suitable means and materials.

As illustrated in FIGS. 2, 5 and 6, the spaced collars and 16 are formed `from arcuately curved plates 15a, 15b, 16a and 16b respectively, each of which are arcuately curved to engage and tit the tubular member 11 on the inner surface thereof. An internally formed hinge is provided for each of the collars 15 and 16 to join the plates 15a, 15b, 16a and 16b respectively, at one end thereof. An end 21 of curved plate 15a and an end 22 of curved plate 15b is provided with a plurality of intermeshed ferrules 23 having openings 24 for receiving and retaining a hinge pin 26. The intermeshed ferrules 23 have portions 23a and 23b that are internally curved or crimped to form the loops on holes 24 and are a part of the ends 21 and 22 of the curved plates 15a and 15b, respectively. It should be noted that while the internally formed hinge 20 of the upper collar 15 has ben described, the internally formed hinge of the lower collar 16 is similar in construction. It should also be noted that with the internally formed hinge 20 of the present invention, the collars 15 and 16 are adapted to be easily removed and positioned on the tubular member 11 and that the internally formed hinge 20 prevents the side bore wall 12a or other suitable means from damaging the structure of the hinge which enables the hinge to be operated at all time except in unusual circumstances.

As illustrated in FIGS. 1, 2, 3, 3A and 6, the other ends 31 and 32 of each of the upper and lower spaced collars 15 and 16 are provided with a plurality of intermeshed tabs or fingers generally designated at 25 each of which is formed so as to provide a plurality of openings 27 as best seen in FIG. 2 for receiving a resilient pin or safety spring pin 30 in the tabs of each collar.

More specifically, the tabs designated generally at 25, include fingers or tabs 25a and 25b on the ends 31 and 32 respectively as illustrated in FIGS. 3 and 3A. The fingers or tabs 25a and 25b are alternately spaced on their respective ends 31 and 32, so that when the ends 31 and 32 are closed or brought towards each other, the tabs 25a and 25b extend into space 34 between the tabs so that the tabs 25a and 25b intert or intermesh with each other. It should be noted that when the tabs 25a and 25b are intermeshed each of the openings 27 therein become substantially aligned for receiving the resilient pin 30 therethrough.

As illustrated in FIGS. 3, 3A, and 4, the resilient pin 30 includes arcuately curved sides 30a and 30b which terminate at their lower ends 30d in close proximity and which are connected together by an upper U-shaped portion 30C to form a generally convex shaped pin. The pin 30 is preferably integrally constructed of spring steel or other suitable material. When the pin 30 is inserted in the aligned openings 27 of the intermeshed tabs 25a and 25b, the lower end 30d of each side 30a and 30b fits in opening 27 but the sides 30a and 30h are spaced so that the distance between them is larger than the width of the opening 27 and therefore the pin 30 must be thereafter forced into the aligned opening 27 to completely fit therein. As illustrated in FIG. 3, when the pin 30 is inserted in the aligned openings 27, each of the sides 30a and 30b are under a compressive force and exert a substantial outwardly compressive force against the ends 36 and 37 of the intermeshed tabs 25b and 25a, respectively. This compressive force securely tightens the collar 15 around the tubular mernber 11 and insures that the inner surface of the collar 15 ts snugly adjacent or contacts the tubular member 11 to inhibit restriction of ow in the annulus. The pin 30 also exerts a sufficient tightening force on the collar 15 to prevent the collar 15 from possibly being drawn out or pulled into the well bore 12 due to the section or pulling force which may be caused by the hydrostatic pressure of the drilling mud or other fluids. However, if the bows 17 engage the well bore wall 12a so as to cause a suicient increase in pressure against the outer surface of the spaced upper collar 15 to radially expand the collar, it will then slide longitudinally relative to the tubular member 11. Thus, as illustrated in FIG. 3A, if the bows 17 become compressed or if any other suitable increased pressure is brought to bear on the collar 15, the ends 36 and 37 of the tabs 25b and 25a, respectively, are forced in the direction indicated by the arrows E and F `which thus compresses the sides 30a and 30h of the pin 30 to bring them closer towards each other. As the sides 30a and 30b are compressed further towards each other, the space, gap or openings 34 increase which means that tabs 25a and 25b have pulled away from each other and that the collar 1,5 has radially expanded and is therefore permitted to slide or move longitudinally relative to the tubular member 11 in response to the compressive force on the bows. Al though the intermeshed tabs 25a and 25b of the collar 15 have been hereinabove described, it is to be understood that the lower spaced collar 16 is provided with similar intermeshed tabs 25a and 25b and a resilient pin 30 for inserting in the aligned openings 27 of the tabs to insure a tight, secure fit of the lower collar 16 around the tubular member 11.

As illustrated in FIG. 8, the lower spaced collar 16 is prevented from radially expanding by a plurality of locking means 38. The locking means 3S includes parallel cuts 38a and 38!) which extend from one edge of the tabs 25a and 25b and transversely thereto. The means 38 is adapted to be bent so that it may be forced into the aligned openings 27 of the lower collar 16 adjacent and between each of the sides 30a and 301: of the pin 30. Therefore if the collar 16 is subjected to substantial increased pressures and the sides 30a and 30h begin to be forced towards each other, the locking means 38 engages and contacts the sides 30a and 30h thereby preventing further movement of the sides towards each other and the intermeshed tabs 25a and 25b on the lower collar 16 are thereby prevented from drawing away from each other ywhich prevents the collar 16 from radially expanding.

As illustrated in FIGS. 5 and 6, a pair of internal pockets or enclosures 40 and 41 are formed in the lower collar 16 for receiving a pair of slips or position members 44 and 43, respectively. The pockets 40 and 41 are arcuately shaped and are positioned in the collar 16 longitudinally relative to the tubular member 11. As illustrated in FIG. 7, one of the slips 43 or 44 is shown as having an outwardly curved back surface 47 for fitting the longitudinal, arcuate contour of the pockets 40and 41. The inner surface 48 of the slips is similarly curved and is provided at each end 48a and 48h with angular teeth or grippers 49 and 50, respectively. It should be noted that the teeth 49 and 50 extend outwardly from the inner surface 48 towards each other so that when the slips 44 and 43 are inserted in the pockets 40 and 41, respectively, the teeth 49 and 50 engage and contact the tubular member 11 to prevent slippage or movement of the collar 16 relative to the tubular member 11.

As illustrated in FIG. 6, a pair of spring bands 53 and 54 are positioned between each of the slips and 43 and 44, respectively for urging the slips outwardly toward the tubular member 11 so that the teeth 49 and 50 continuously engage the member 11.\The bands 53 and 54 are positioned adjacent and between the inner curved surface of each of the pockets 41 and 40, respectively and the back surface 47 of each of the slips 43 and 44. Normally the spring bands 53 and 54 are not arcuate and therefore when forced to conform to the arcuate curve of the pockthe retainer pins 57 and 58, respectively, as best illustrated in FIG. 6, to enable the pins to contact and engage the inner surface 48 of the slips 44 and 43 substantially at the center of and transversely thereto so that the slips 43, 44 and bands 53, 54 are retained in the pockets 41, 40 respectively.

In the operation of the invention and as mentioned previously, the spring bands 53 and 54 and slips 43, 44 are inserted and positioned in the pockets 41 and 40, respectively, and are held in the pockets by the retainer pins 57 and 58 which are inserted through the openings 60 and 59 respectively.

The plates 15a and 15b and 16a, 16b are outwardly, radially expanded and pivot around the internal hinge 20 to be positioned around the tubular member 11. The tabs 25a and 25h of each of the upper and lower collars 15 and 16 are thereafter closed toward each other to become intermeshed so that the openings 27 of each of the tabs with the upper and lower collars 15 and 16, respectively, are substantially aligned to receive the resilient pins 30. The sides 30a and 301; of the pins are substantially further apart than the diameter of the openings 27 and thus, the pins 30 must be forcibly inserted in the aligned openings 27.

After the pins 30 are forcibly inserted in the openings Z7, the sides 30a and 30b are under substantial compression and exert an outward force on the ends 37 and 36, respectively of the tabs or fingers 25 to cause the collars 15 and 16 to radially contact and snugly fit adjacent the tubular member 11.

-The locking means 38 on the lower collar 16 is then forced into the aligned openings 27 with the lower collar 16 to prevent the lower collar from thereafter radially expanding due to increased pressures on the lower collar and/or increased pressure on the bows 17 after the centralizer is inserted inthe well bore 12.

After the centralizer 10 is properly positioned around the tubular member 11, the tubular member 11 is inserted in the well bore in a manner well known in the art. The centralizer bows 17 contact the walls 12a of the well bore 12 to center the tubular member 11 therein, and drilling mud or other suitable tiuids are then pumped upwardly or downwardly in the well bore therepast the centralizer 10.

The collar is adapted to radially expand and slide longitudinally relative to the tubular member 11 and the lower collar 16 if there is a suiiicient increase in pressure on the collar 15 or if the bows 17 become compressed due to decreasing diameter of the Well bore 12.

Thus, when the pressure on the collar 15 increases sufciently, the tabs 25a and 25h pull away from each other causing the ends 37 and 36 to pull sides 30b and 30a towards each other to permit the collar to expand thereby'enabling the collar 15 to move upwardly or downwardly in response to the substantially increased pressure.

However, as mentioned hereinabove, the lower collar 16'is prevented from radially expanding because of the locking means 38 which is positioned between the'sides 30a and 30h of the pin 30 to prevent the sides from being forced towards each other by the ends 36 and 37 of the intermeshed tabs 25. Also, the lower collar 16 is irmly positioned around the tubular member 11 and remains stationary due to the teeth 49 and 50 of the slips 43 and 44 which engage and grip the tubular member 11. The teeth 49 and 50 are angularly disposed towards each other and are positioned longitudinally relative to the slips and tubular member 11 so that they prevent the collar from slipping longitudinally upwardly or downwardly along the tubular member 11. It should be noted that the spring bands 53 and 54 Iurge the slips 43 and 44, respectively, continuously outwardly to enable the teeth 49 and 50 to continuously engage and contact 'the tubular member 11.

It should also be noted that all of the outer surface of the centralizer 10 that is exposed to fluid flow and the well bore wall 12a is curved to prevent undue restriction of 1tlhe fluid ow and to prevent gouging of the well bore wa Briefly, the present invention relates to a centralizer for positioning around a tubular member in a well bore including an upper collar adapted to expand radially and slide longitudinally in response to suiiicient pressures and a. lower collar having slips and a locking means for xedly securing it to the tubular member and a plurality of spaced, centralizer bows secured to each of the collars and mounted therebetween for centering the tubular member in the well bore.

Accordingly, and within the spirit of my invention, what is claimed is:

1. A centralizer for positioning with a tubular member in a well bore comprising:

(a) an upper collar positioned on the tubular member,

(b) a lower collar positioned on the tubular member and spaced from said upper collar,

(c) internally formed hinges secured to each of said collars for protecting each of said hinges from damage from the well bore and for enabling each of said collars to be easily positioned on and removed from the tubular member,

(d) spaced bows having arcuate portions therein, said bows being secured to each of said collars and mounted therebetween wherein the arcuate portions of said spaced bows engage the sides of the well bore to center the tubular member in the well bore,

(e) intermeshed tabs having aligned openings therein mounted with each of said upper and lower collars, and

(f) a resilient pin having convex sides and an upper portion joining the sides, one of each of said pins being forcibly inserted in said aligned openings of said intermeshed tabs thereby reducing the clearance between each of said collars and the tubular member to a minimum clearance which reduces the annulus between the tubular member and tse sides of the well bore to enable uids to flow freely therethrough.

2. The structure as set forth in claim 1 wherein said convex sides of each of said pins are under compression when inserted in said openings of said intermeshed tabs and wherein increased pressure on said collars causes said intermeshed tabs to pull outwardly which substantially increases the compression on said convex sides of each of said pins to push said sides closer together to thereby enable said collars to expand radially outwardly relative to the tubula-r member.

3. The structure as set forth in claim 2 including locking means secured to said intermeshed tabs mounted with said lower collar for forcing into said aligned openings to thereby prevent said sides of said pin inserted in said openings of said tabs with said lower collar from pushing closer together when pressure is increased on said lower collar whereby said lower collar is prevented from radially expanding in response to substantially increased pressures in the well bore.

4. The structure as set forth in claim 3 including:

(a) a plurality of pockets formed on the inner surface of said lower collar,

(b) a plurality of slips, one of each of said slips being inserted in one of each of said pockets wherein said slips contact and engage the tubular member to prevent said lower collar from slipping longitudinally relative to the tubular member, and

(c) means releasably secured to said lower collar for retaining said slips in said pockets.

5. The structure as set forth in claim 4 wherein said spaced bows become compressed because of reduction in the size of the well bore which thereby increases the pressure on said collars to thereby cause said upper collar to radially expand and enable it to slide longitudinally on the tubular member to reduce the compression in said bows and whereby said lower collar is prevented from radially expanding because of said locking means and said plurality of slips thereby positions said lower collar on the tubular member in a xed position.

6. A centralizer for position around a tubular member in a well bore comprising:

(a) an upper collar positioned around the tubular member,

(b) a lower collar positioned around the tubular member,

(c) spaced bows having arcuate portions therein, said bows being secured to each of said collars vand mounted therebetween wherein the arcuate portions of said spaced bows engage the sides of the well bore to center the tubular member in the well bore,

(d) means with said lower collar for positioning said lower collar around the tubular member in a fixed position wherein said upper collar is permitted to move relative to said lower collar in response to pressures from uids and the well bore,

(e) intermeshed tabs having aligned openings therein mounted with each of said upper and lower collars, and

(f) a resilient pin having convex sides and an upper portion joining the sides, one of each of said pins being forcibly inserted in said` aligned openings of said intermeshed tabs thereby reducing the clearance between each of said collars and the tubular member to a minimum clearance which reduces the annulus between the tubular member and the sides of the well bore to enable fiuids to flow freely therethrough.

7. Thestructure as set forth in claim 6 wherein said convex sides of said pin with said upper collar are under substantial compression when inserted in said openingA of said intermeshed tabs with said upper collar and wherein increased pressure on said upper collar causes said intermeshed tabs with said upper collar to pull outwardly which substantially increases the compression on said convex sides of said pin to push said side closer together to thereby enable said upper collar to expand radially and move relative to said lower collar.

8. The structure as set forth in claim 7 including locking means for preventing said lower collar from radially expanding.

References Cited UNITED STATES PATENTS 3,055,432 9/1962 Park 166-241 3,124,196 3/1964 Solurn 16624l 3,200,884 8/1965 Solum et al 166--241 3,289,767 12/1966 Seward et al 166--241 X JAMES A. LEPPINK, Primary Examiner. 

1. A CENTRALIZER FOR POSITIONING WITH A TUBULAR MEMBER IN A WELL BORE COMPRISING: (A) AN UPPER COLLAR POSITIONED ON THE TUBULAR MEMBER, (B) A LOWER COLLAR POSITIONED ON THE TUBULAR MEMBER AND SPACED FROM SAID UPPER COLLAR, (C) INTERNALLY FORMED HINGES SECURED TO EACH OF SAID COLLARS FOR PROTECTING EACH OF SAID HINGES FROM DAMAGE FROM THE WELL BORE AND FOR ENABLING EACH OF SAID COLLARS TO BE EASILY POSITIONED ON AND REMOVED FROM THE TUBULAR MEMBER, (D) SPACED BOWS HAVING ARCUATE PORTIONS THEREIN, SAID BOWS BEING SECURED TO EACH OF SAID COLLARS AND MOUNTED THEREBETWEEN WHEREIN THE ARCUATE PORTIONS OF SAID SPACED BOWS ENGAGE THE SIDES OF THE WELL BORE TO CENTER THE TUBULAR MEMBER IN THE WELL BORE, (E) INTERMESHED TABS HAVING ALIGNED OPENINGS THEREIN MOUNTED WITH EACH OF SAID UPPER AND LOWER COLLARS AND (F) A RESILIENT PIN HAVING CONVEX SIDES AND AN UPPER PORTION JOINING THE SIDES, ONE OF EACH OF SAID PINS BEING FORCIBLY INSERTED IN SAID ALIGNED OPENINGS OF SAID INTERMESHED TABS THEREBY REDUCING THE CLEARANCE BETWEEN EACH OF SAID COLLARS AND THE TUBULAR MEMBER TO A MINIMUM CLEARANCE WHICH REDUCES THE ANNULUS BETWEEN THE TUBULAR MEMBER AND TSE SIDES OF THE WELL BORE TO ENABLE FLUIDS TO FLOW FREELY THERETHROUGH. 